The present invention relates generally to methods and systems for investigating the properties of fluids using electromagnetic energy, and more particularly but not by way of limitation to investigating methods and systems for measuring one or more properties of wellbore fluids, properties of multiphase flows, properties of production fluids, properties of fluid flows in pipelines/conduits, properties of fluids in earth formation and/or the like. Merely by way of example, the described methods and systems may be used to enhance a penetration of electromagnetic energy transmitted within a material to enhance and investigation depth, and in some examples the enhanced investigation may be used in the wellbore to enhance the measurement of the one or more properties of the wellbore and/or fluids flowing in/out of the wellbore.
Various tools and devices are currently used within wellbores and pipelines/conduits to measure properties of fluids flowing therein. Determining flow properties of multiphase mixtures flowing in the wellbores and pipelines/conduits—such as flow velocity, percentages/ratios of the different phases, volume flow rate of a phase and/or the like—may be used to determine an amount of a phase, such as an oil phase, a water phase, a gas phase, a solids phase being carried in the wellbore/pipeline/conduit or contained in earth formation etc., identify presence/quantities of a phase at a location along the wellbore/pipeline/conduit etc. and/or the like.
Radio frequency (“RF”) antennas, microwave antennas and/or the like have been used as part of multiphase flow metering systems. For example, U.S. Pat. No. 7,624,652 and U.S. Pat. No. 8,224,588 disclose the use of electromagnetic antennas, for example a plurality of electric-dipole antennas, for the measurement of phase fraction(s) of a multiphase flow and/or water conductivity. U.S. Pat. No. 6,915,707 discloses a multiphase flow sensor pipe-section with an integrated mechanical structure serving as a microwave resonator sensor for providing permittivity measurements of the multiphase flow, which measurements may be used to determine properties of the multiphase flow/phases of the multiphase flow (the mechanical structure also functions as a differential pressure element for providing flow rate measurements).
Transmission-reception electromagnetic antennas have been explored for multiphase flow phase fraction and/or water-cut measurement (see, e.g., U.S. Pat. No. 7,908,930, and U.S. Patent Pub No. 20110267074) and for tomographic flow imaging (see, e.g., U.S. Pat. No. 5,485,743), and/or for phase velocity measurement based on Doppler sensing (see, e.g., GB Patent No. 2 359 435 and U.S. Pat. No. 7,712,380) or cross-correlation measurements (see, e.g., U.S. Pat. No. 7,908,930). RF/microwave reflection probe and/or transmission antennas have also been used for measuring water conductivity of multiphase flows (see, e.g., U.S. Pat. No. 6,831,470). Electromagnetic systems have also been used to investigate investigate formation-fluids, such as described in European patent/patent application EP 2 015 109. An apparatus for determining a property of a downhole formation may comprise an array having a plurality of transmitters and receivers capable of propagating electromagnetic waves through the formation. Furthermore, electromagnetic investigation systems may be used to investigate properties of a solid phase contained in or being carried in a liquid/fluid phase. The content of the patents referenced above are incorporated by reference herein for all purposes.